<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        body {
            min-height: 100vh;
            background-color: #abefe9;
        }

        body>div {
            margin: 5px;
            border: #bfa 3px solid;
        }

        hr {
            background-color: red;
            height: 1px;
            border: 0;
        }

        .d1 {
            height: 100px;
            overflow: hidden;
        }

        .d1>div {
            height: 100px;
            width: 100px;
            margin-right: 5px;
            float: left;
        }

        .d11 {
            background-image: linear-gradient(red, yellow);
        }

        .d12 {
            background-image: linear-gradient(to left, #28e, red, yellow);
        }

        .d13 {
            background-image: linear-gradient(45deg, #233, red, yellow);
        }

        .d14 {
            background-image: linear-gradient(red 20px, yellow 80px);
        }

        .d21 {
            background-image: radial-gradient(red, yellow);
        }

        .d22 {
            /* ？？？？ */
            background-image: radial-gradient(ellipse, red, yellow);
        }

        .d23 {
            background-image: radial-gradient(50px 50px, red, yellow);
        }

        .d24 {
            background-image: radial-gradient(50px 50px at 0 50px, red, yellow);
        }
    </style>


</head>

<body>
    <div class="d1">
        <div class="d11"></div>
        <div class="d12"></div>
        <div class="d13"></div>
        <div class="d14"></div>
    </div>
    <div class="d1">
        <div class="d21"></div>
        <div class="d22"></div>
        <div class="d23"></div>
        <div class="d24"></div>
    </div>
</body>

</html>